This is a program project application for research in pelvic inflammatory disease (PID) and Chlamydial infection. The project includes a Core and three research projects: Specific chlamydia protein in PID sequelae; Consequences of PID; and Evaluation of therapeutic regimens for treatment of PID; Clinical response and microbiologic cure. The core brings together clinical facilities (Reproductive Infectious Diseases, SFGH; City Clinic, San Francisco; Adolescent Medicine, UCSF) clinically and epidemiologically oriented investigations on pelvic inflammatory disease, Chlamydia, N. gonorrhoeae infection, and other STD organisms, and the STD Training Program. In turn, these clinical and epidemiologic programs provide excellent opportunities for collaboration with basic science research activities of the Bay Area STD Research Program. The integration of these research resources provides an environment with an excellent balance between clinical and basic science investigation. East of the research projects will make use of the Core resources to enhance our understanding of pelvic inflammatory disease and chlamydial infection.